Key information relevant to the recruitment process for the
overall study, such as dates of the recruitment period and locations

The study was conducted under a waiver of informed consent for emergency research that was approved by the U.S. Food and Drug Administration and by the Institutional Review Boards at participating study sites. All adults with out-of-hospital cardiac arrest were eligible for the study.

Pre-Assignment Details

Significant events and approaches for the overall study
following participant enrollment, but prior to group assignment

All sites were required to complete a run-in phase prior to to beginning randomization. A total of 197 patients were enrolled in the run-in phase across all sites. A total of 2470 patients were provisionally enrolled and received randomized CPR treatment. Of these, 1653 met the final selection criteria (non-traumatic arrest due to cardiac cause).

Explanation of how the number of participants for analysis was determined.
Includes whether analysis was per protocol, intention to treat, or another method.
Also provides relevant details such as imputation technique, as appropriate.

Number of Patients Who Survived to Hospital Discharge With Favorable Neurologic Function Defined as MRS Score <=3 [ Time Frame: When the subject is discharged from the hospital; an average of 12 days after cardiac arrest for subjects surviving to hospital discharge ]

Major Adverse Event Rate as Measured by Number of Patients With One or More Adverse Events [ Time Frame: Time from cardiac arrest through hospital discharge (an average of 12 days for subjects surviving to hospital discharge ]